ObjFW  Artifact [d0c4634748]

Artifact d0c4634748c0764dd763221816c2894ba2b434fdeda5f3b843eaf7880b5bce48:

• File src/OFSecureData.m — part of check-in [96f946d7ad] at 2024-05-09 10:21:24 on branch trunk — Use unsigned long for bit sets

  This should be more efficient on some architectures.

  As a nice side effect, this is also what Linux does in some userspace
  APIs, so after this change, these macros can be used for this as well
  (and Linux interestingly does not provide similar macros in the
  userspace headers). (user: js, size: 15198) [annotate] [blame] [check-ins using] [more...]

/*
 * Copyright (c) 2008-2024 Jonathan Schleifer <js@nil.im>
 *
 * All rights reserved.
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version 3.0 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
 * version 3.0 for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3.0 along with this program. If not, see
 * <https://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <errno.h>
#include <stdlib.h>

#ifdef HAVE_SYS_MMAN_H
# include <sys/mman.h>
#endif

#import "OFSecureData.h"
#import "OFString.h"
#import "OFSystemInfo.h"
#ifdef OF_HAVE_THREADS
# import "OFTLSKey.h"
#endif

#import "OFInitializationFailedException.h"
#import "OFInvalidArgumentException.h"
#import "OFNotImplementedException.h"
#import "OFOutOfMemoryException.h"
#import "OFOutOfRangeException.h"

#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
static const size_t chunkSize = 16;

struct Page {
	struct Page *next, *previous;
	unsigned long *map;
	unsigned char *page;
};

# if defined(OF_HAVE_COMPILER_TLS)
static thread_local struct Page *firstPage = NULL;
static thread_local struct Page *lastPage = NULL;
static thread_local struct Page **preallocatedPages = NULL;
static thread_local size_t numPreallocatedPages = 0;
# elif defined(OF_HAVE_THREADS)
static OFTLSKey firstPageKey, lastPageKey;
static OFTLSKey preallocatedPagesKey, numPreallocatedPagesKey;
# else
static struct Page *firstPage = NULL;
static struct Page *lastPage = NULL;
static struct Page **preallocatedPages = NULL;
static size_t numPreallocatedPages = 0;
# endif

static void *
mapPages(size_t numPages)
{
	size_t pageSize = [OFSystemInfo pageSize];
	void *pointer;

	if (numPages > SIZE_MAX / pageSize)
		@throw [OFOutOfRangeException exception];

	if ((pointer = mmap(NULL, numPages * pageSize, PROT_READ | PROT_WRITE,
	    MAP_PRIVATE | MAP_ANON, -1, 0)) == MAP_FAILED)
		@throw [OFOutOfMemoryException
		    exceptionWithRequestedSize: numPages * pageSize];

	if (mlock(pointer, numPages * pageSize) != 0) {
		munmap(pointer, numPages * pageSize);
		@throw [OFOutOfMemoryException
		    exceptionWithRequestedSize: numPages * pageSize];
	}

	return pointer;
}

static void
unmapPages(void *pointer, size_t numPages)
{
	size_t pageSize = [OFSystemInfo pageSize];

	if (numPages > SIZE_MAX / pageSize)
		@throw [OFOutOfRangeException exception];

	munlock(pointer, numPages * pageSize);
	munmap(pointer, numPages * pageSize);
}

static struct Page *
addPage(bool allowPreallocated)
{
	size_t pageSize = [OFSystemInfo pageSize];
	size_t mapSize = OFRoundUpToPowerOf2(OF_ULONG_BIT,
	    pageSize / chunkSize) / OF_ULONG_BIT;
	struct Page *page;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	struct Page *lastPage;
# endif

	if (allowPreallocated) {
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
		uintptr_t numPreallocatedPages =
		    (uintptr_t)OFTLSKeyGet(numPreallocatedPagesKey);
# endif

		if (numPreallocatedPages > 0) {
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
			struct Page **preallocatedPages =
			    OFTLSKeyGet(preallocatedPagesKey);
# endif

			numPreallocatedPages--;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
			OFEnsure(OFTLSKeySet(numPreallocatedPagesKey,
			    (void *)numPreallocatedPages) == 0);
# endif

			page = preallocatedPages[numPreallocatedPages];

			if (numPreallocatedPages == 0) {
				OFFreeMemory(preallocatedPages);
				preallocatedPages = NULL;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
				OFEnsure(OFTLSKeySet(preallocatedPagesKey,
				    preallocatedPages) == 0);
# endif
			}

			return page;
		}
	}

	page = OFAllocMemory(1, sizeof(*page));
	@try {
		page->map = OFAllocZeroedMemory(mapSize, sizeof(unsigned long));
	} @catch (id e) {
		OFFreeMemory(page);
		@throw e;
	}
	@try {
		page->page = mapPages(1);
	} @catch (id e) {
		OFFreeMemory(page->map);
		OFFreeMemory(page);
		@throw e;
	}
	OFZeroMemory(page->page, pageSize);

# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	lastPage = OFTLSKeyGet(lastPageKey);
# endif

	page->previous = lastPage;
	page->next = NULL;

	if (lastPage != NULL)
		lastPage->next = page;

# if defined(OF_HAVE_COMPILER_TLS) || !defined(OF_HAVE_THREADS)
	lastPage = page;

	if (firstPage == NULL)
		firstPage = page;
# else
	OFEnsure(OFTLSKeySet(lastPageKey, page) == 0);

	if (OFTLSKeyGet(firstPageKey) == NULL)
		OFEnsure(OFTLSKeySet(firstPageKey, page) == 0);
# endif

	return page;
}

static void
removePageIfEmpty(struct Page *page)
{
	unsigned long *map = page->map;
	size_t pageSize = [OFSystemInfo pageSize];
	size_t mapSize = OFRoundUpToPowerOf2(OF_ULONG_BIT,
	    pageSize / chunkSize) / OF_ULONG_BIT;

	for (size_t i = 0; i < mapSize; i++)
		if (map[i] != 0)
			return;

	unmapPages(page->page, 1);
	OFFreeMemory(page->map);

	if (page->previous != NULL)
		page->previous->next = page->next;
	if (page->next != NULL)
		page->next->previous = page->previous;

# if defined(OF_HAVE_COMPILER_TLS) || !defined(OF_HAVE_THREADS)
	if (firstPage == page)
		firstPage = page->next;
	if (lastPage == page)
		lastPage = page->previous;
# else
	if (OFTLSKeyGet(firstPageKey) == page)
		OFEnsure(OFTLSKeySet(firstPageKey, page->next) == 0);
	if (OFTLSKeyGet(lastPageKey) == page)
		OFEnsure(OFTLSKeySet(lastPageKey, page->previous) == 0);
# endif

	OFFreeMemory(page);
}

static void *
allocateMemory(struct Page *page, size_t bytes)
{
	size_t chunks, chunksLeft, pageSize, i, firstChunk;

	bytes = OFRoundUpToPowerOf2(chunkSize, bytes);
	chunks = chunksLeft = bytes / chunkSize;
	firstChunk = 0;
	pageSize = [OFSystemInfo pageSize];

	for (i = 0; i < pageSize / chunkSize; i++) {
		if (OFBitSetIsSet(page->map, i)) {
			chunksLeft = chunks;
			firstChunk = i + 1;
			continue;
		}

		if (--chunksLeft == 0)
			break;
	}

	if (chunksLeft == 0) {
		for (size_t j = firstChunk; j < firstChunk + chunks; j++)
			OFBitSetSet(page->map, j);

		return page->page + (chunkSize * firstChunk);
	}

	return NULL;
}

static void
freeMemory(struct Page *page, void *pointer, size_t bytes)
{
	size_t chunks, chunkIndex;

	bytes = OFRoundUpToPowerOf2(chunkSize, bytes);
	chunks = bytes / chunkSize;
	chunkIndex = ((uintptr_t)pointer - (uintptr_t)page->page) / chunkSize;

	OFZeroMemory(pointer, bytes);

	for (size_t i = 0; i < chunks; i++)
		OFBitSetClear(page->map, chunkIndex + i);
}
#endif

@implementation OFSecureData
@synthesize allowsSwappableMemory = _allowsSwappableMemory;

#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON) && \
    !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
+ (void)initialize
{
	if (self != [OFSecureData class])
		return;

	if (OFTLSKeyNew(&firstPageKey) != 0 || OFTLSKeyNew(&lastPageKey) != 0 ||
	    OFTLSKeyNew(&preallocatedPagesKey) != 0 ||
	    OFTLSKeyNew(&numPreallocatedPagesKey) != 0)
		@throw [OFInitializationFailedException
		    exceptionWithClass: self];
}
#endif

+ (void)preallocateUnswappableMemoryWithSize: (size_t)size
{
#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
	size_t pageSize = [OFSystemInfo pageSize];
	size_t numPages = OFRoundUpToPowerOf2(pageSize, size) / pageSize;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	struct Page **preallocatedPages = OFTLSKeyGet(preallocatedPagesKey);
	size_t numPreallocatedPages;
# endif
	size_t i;

	if (preallocatedPages != NULL)
		@throw [OFInvalidArgumentException exception];

	preallocatedPages = OFAllocZeroedMemory(numPages, sizeof(struct Page));
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	OFEnsure(OFTLSKeySet(preallocatedPagesKey, preallocatedPages) == 0);
# endif

	@try {
		for (i = 0; i < numPages; i++)
			preallocatedPages[i] = addPage(false);
	} @catch (id e) {
		for (size_t j = 0; j < i; j++)
			removePageIfEmpty(preallocatedPages[j]);

		OFFreeMemory(preallocatedPages);
		preallocatedPages = NULL;

		@throw e;
	}

	numPreallocatedPages = numPages;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	OFEnsure(OFTLSKeySet(numPreallocatedPagesKey,
	    (void *)(uintptr_t)numPreallocatedPages) == 0);
# endif
#else
	@throw [OFNotImplementedException exceptionWithSelector: _cmd
							 object: self];
#endif
}

+ (instancetype)dataWithCount: (size_t)count
	allowsSwappableMemory: (bool)allowsSwappableMemory
{
	return [[[self alloc] initWithCount: count
		      allowsSwappableMemory: allowsSwappableMemory]
	    autorelease];
}

+ (instancetype)dataWithCount: (size_t)count
		     itemSize: (size_t)itemSize
	allowsSwappableMemory: (bool)allowsSwappableMemory
{
	return [[[self alloc] initWithCount: count
				   itemSize: itemSize
		      allowsSwappableMemory: allowsSwappableMemory]
	    autorelease];
}

+ (instancetype)dataWithItems: (const void *)items count: (size_t)count
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (instancetype)dataWithItems: (const void *)items
			count: (size_t)count
		     itemSize: (size_t)itemSize
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (instancetype)dataWithItemsNoCopy: (void *)items
			      count: (size_t)count
		       freeWhenDone: (bool)freeWhenDone
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (instancetype)dataWithItemsNoCopy: (void *)items
			      count: (size_t)count
			   itemSize: (size_t)itemSize
		       freeWhenDone: (bool)freeWhenDone
{
	OF_UNRECOGNIZED_SELECTOR
}

#ifdef OF_HAVE_FILES
+ (instancetype)dataWithContentsOfFile: (OFString *)path
{
	OF_UNRECOGNIZED_SELECTOR
}
#endif

+ (instancetype)dataWithContentsOfIRI: (OFIRI *)IRI
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (instancetype)dataWithStringRepresentation: (OFString *)string
{
	OF_UNRECOGNIZED_SELECTOR
}

+ (instancetype)dataWithBase64EncodedString: (OFString *)string
{
	OF_UNRECOGNIZED_SELECTOR
}

- (instancetype)initWithCount: (size_t)count
	allowsSwappableMemory: (bool)allowsSwappableMemory
{
	return [self initWithCount: count
			  itemSize: 1
	     allowsSwappableMemory: allowsSwappableMemory];
}

- (instancetype)initWithCount: (size_t)count
		     itemSize: (size_t)itemSize
	allowsSwappableMemory: (bool)allowsSwappableMemory
{
	self = [super init];

	@try {
#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
		size_t pageSize = [OFSystemInfo pageSize];
#endif

		if (count > SIZE_MAX / itemSize)
			@throw [OFOutOfRangeException exception];

		if (allowsSwappableMemory) {
			_items = OFAllocMemory(count, itemSize);
			_freeWhenDone = true;
			memset(_items, 0, count * itemSize);
#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
		} else if (count * itemSize >= pageSize)
			_items = mapPages(OFRoundUpToPowerOf2(pageSize,
			    count * itemSize) / pageSize);
		else {
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
			struct Page *lastPage = OFTLSKeyGet(lastPageKey);
# endif

			for (struct Page *page = lastPage; page != NULL;
			    page = page->previous) {
				_items = allocateMemory(page, count * itemSize);

				if (_items != NULL) {
					_page = page;
					break;
				}
			}

			if (_items == NULL) {
				_page = addPage(true);
				_items = allocateMemory(_page,
				    count * itemSize);

				if (_items == NULL)
					@throw [OFOutOfMemoryException
					    exceptionWithRequestedSize:
					    count * itemSize];
			}
		}
#else
		} else
			@throw [OFNotImplementedException
			    exceptionWithSelector: _cmd
					   object: nil];
#endif

		_count = count;
		_itemSize = itemSize;
		_allowsSwappableMemory = allowsSwappableMemory;
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (instancetype)init
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithItemSize: (size_t)itemSize
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithItems: (const void *)items count: (size_t)count
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithItems: (const void *)items
			count: (size_t)count
		     itemSize: (size_t)itemSize
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithItemsNoCopy: (void *)items
			      count: (size_t)count
		       freeWhenDone: (bool)freeWhenDone
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithItemsNoCopy: (void *)items
			      count: (size_t)count
			   itemSize: (size_t)itemSize
		       freeWhenDone: (bool)freeWhenDone
{
	OF_INVALID_INIT_METHOD
}

#ifdef OF_HAVE_FILES
- (instancetype)initWithContentsOfFile: (OFString *)path
{
	OF_INVALID_INIT_METHOD
}
#endif

- (instancetype)initWithContentsOfIRI: (OFIRI *)IRI
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithStringRepresentation: (OFString *)string
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithBase64EncodedString: (OFString *)string
{
	OF_INVALID_INIT_METHOD
}

- (void)dealloc
{
	[self zero];

#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
	if (!_allowsSwappableMemory) {
		size_t pageSize = [OFSystemInfo pageSize];

		if (_count * _itemSize > pageSize)
			unmapPages(_items,
			    OFRoundUpToPowerOf2(pageSize, _count * _itemSize) /
			    pageSize);
		else if (_page != NULL) {
			if (_items != NULL)
				freeMemory(_page, _items, _count * _itemSize);

			removePageIfEmpty(_page);
		}
	}
#endif

	if (_freeWhenDone)
		OFFreeMemory(_items);

	[super dealloc];
}

- (size_t)count
{
	return _count;
}

- (size_t)itemSize
{
	return _itemSize;
}

- (const void *)items
{
	return _items;
}

- (void *)mutableItems
{
	return _items;
}

- (void *)mutableItemAtIndex: (size_t)idx
{
	if (idx >= _count)
		@throw [OFOutOfRangeException exception];

	return _items + idx * _itemSize;
}

- (void)zero
{
	OFZeroMemory(_items, _count * _itemSize);
}

- (id)copy
{
	OFSecureData *copy = [[OFSecureData alloc]
		    initWithCount: _count
			 itemSize: _itemSize
	    allowsSwappableMemory: _allowsSwappableMemory];

	memcpy(copy.mutableItems, _items, _count * _itemSize);

	return copy;
}

- (id)mutableCopy
{
	OFSecureData *copy = [[OFSecureData alloc]
		    initWithCount: _count
			 itemSize: _itemSize
	    allowsSwappableMemory: _allowsSwappableMemory];

	memcpy(copy.mutableItems, _items, _count * _itemSize);

	return copy;
}

- (bool)isEqual: (id)object
{
	OFData *otherData;
	const unsigned char *otherDataItems;
	unsigned char diff;

	if (object == self)
		return true;

	if (![object isKindOfClass: [OFData class]])
		return false;

	otherData = object;
	otherDataItems = otherData.items;

	if (otherData.count != _count || otherData.itemSize != _itemSize)
		return false;

	diff = 0;

	for (size_t i = 0; i < _count * _itemSize; i++)
		diff |= otherDataItems[i] ^ _items[i];

	return (diff == 0);
}

- (OFString *)description
{
	return @"<OFSecureData>";
}

- (OFString *)stringRepresentation
{
	OF_UNRECOGNIZED_SELECTOR
}

- (OFString *)stringByBase64Encoding
{
	OF_UNRECOGNIZED_SELECTOR
}

#ifdef OF_HAVE_FILES
- (void)writeToFile: (OFString *)path
{
	OF_UNRECOGNIZED_SELECTOR
}
#endif

- (void)writeToIRI: (OFIRI *)IRI
{
	OF_UNRECOGNIZED_SELECTOR
}

- (OFData *)messagePackRepresentation
{
	OF_UNRECOGNIZED_SELECTOR
}
@end